Birds: Not bird brains?
Researchers are now beginning to appreciate the complexity of bird's cognitive structure and abilities. For years, scientists have known birds to be highly sensitive to electromagnetism, and many have suggested that birds travel from north-south and south-north as seasons change by following electromagnetic grid lines radiating from the poles. Birds also have an impressive array of measurable cognitive abilities..
By LEE BOWMAN
Scripps Howard News Service
February 21, 2005
Birds' brain structures are now appreciated as being nearly as sophisticated as humans'. So of course the next logical question might be: Are all birds of a feather the same in the thinking department?
A Canadian biologist has come up with a rating system for bird-braininess, based not on a mere peck or two in a lab cage, but observations of the birds' own natural behavior in the wild.
Louis Lefebvre, an animal behaviorist at McGill University in Montreal, tapped into more than 70 years of observations recorded by the world's bird-watchers to develop his bird IQ test. He got more than 2,000 reports on 500 animals.
Most of the birders' "field notes" deal with feeding behavior, and the culinary habits are certainly wide-ranging, from English tits that have mastered the skill of opening foil bottle caps of milk bottles left on stoops so they can get at the cream, to Rhodesian vultures that learned to wait around mine fields until an unsuspecting gazelle was blown into a meal.
"Previous attempts to establish animal intelligence used standardized IQ-style tests, which were unfair to certain species and out of touch with real-life situations," Lefebvre said. "We had to find a whole new way of measuring intelligence," he told a seminar on animal behavior Monday at the annual meeting of the American Association for the Advancement of Science.
The index statistically takes into account differences in the number of observations for commonly seen birds, such as crows, and rare, isolated sightings, compiling a profile for each species.
"Initially, quite honestly, I didn't think it would work," said Lefebvre, who first reported his work eight years ago. "Scientists don't like anecdotal evidence. So if you're wary of one anecdote, why would you expect to find a valid pattern in 2,000? I've been waiting for something to come up that would invalidate the system, but nothing has."
Three years ago, British researchers further validated the feeding innovation index methodology by applying it to primates.
The result, Lefebvre said, is a clear indication in both groups that greater feeding innovation, tool use and speed of learning are related to having larger forebrains. "Similar solutions to brain-cognition organization seem to have evolved in two groups whose ancestors diverged more than 300 million years ago," he said.
One of the better illustrations of brain size and intelligence matching up comes in the common crow, which has one of the higher brain-body size ratios. Taking into account total body-weight differences, the crow's brain is about five times larger than that of a pigeon, and ranks, along with falcons, at the top of the bird class, followed by hawks, woodpeckers and herons.
In Japan, one species of crow sits around intersections waiting for cars to stop, then swoops down and puts walnuts they want to eat under the cars' tires, and then flit away until their meal is opened.
Bald eagles in northern Arizona have been seen chipping holes in ice over frozen ponds beneath which dead minnows are trapped. Once they make a hole, the eagles jump up and down on the ice to push the minnows up through the holes.